Dtc B2278 Engine Switch Circuit Malfunction

Engine. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35
2Az-Fe Starting. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (START SWITCH 1 AND 2)

CHECK SWITCH CONDITION (ENGINE SWITCH)

INSPECT ENGINE SWITCH

CHECK HARNESS AND CONNECTOR (ENGINE SWITCH - MAIN BODY ECU AND BODY GROUND)

DTC B2278 Engine Switch Circuit Malfunction


DESCRIPTION

This DTC is stored when 1) a malfunction is detected between the main body ECU and engine switch; or 2) either of the switches inside the engine switch is malfunctioning.

DTC Code
DTC Detection Condition
Trouble Area
B2278
Communication is abnormal between the main body ECU and engine switch or the engine switch is defective.
  1. Main body ECU
  2. Engine switch
  3. Harness or connector

WIRING DIAGRAM


Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.2Az-Fe Starting.Starting System (W/ Entry And Start System). Dtc B2278 Engine Switch Circuit Malfunction


INSPECTION PROCEDURE

1.READ VALUE USING INTELLIGENT TESTER (START SWITCH 1 AND 2)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the intelligent tester on.

  1. Enter the following menus: Body / Main Body / Data List.

  1. Read the value displayed on the intelligent tester.

    Main Body
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Start Switch1
    		Start Switch 1/ON or OFF
    		ON: Engine switch on (IG)
    OFF: Engine switch off
    		-
    Start Switch2
    		Start Switch 2/ON or OFF
    		ON: Engine switch on (IG)
    OFF: Engine switch off
    		-
    OK:
    When the engine switch is turned on (IG), ON appears on the intelligent tester screen.


NG
Go to step 3
OK


2.CHECK SWITCH CONDITION (ENGINE SWITCH)

  1. Make sure that the electrical key is inside the cabin.

  1. With the shift lever in P, check that the power source mode changes as shown below each tine the engine switch is pushed.

    OK:
    off → on (ACC) → on (IG) → off


NG
GO TO POWER SOURCE MODE DOES NOT CHANGE (RAV4_ACA30 RM000000Y7X01OX.html)
OK

USE SIMULATION METHOD TO CHECK (RAV4_ACA30 RM000000UZ306OX.html)

3.INSPECT ENGINE SWITCH


    Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.2Az-Fe Starting.Starting System (W/ Entry And Start System). Dtc B2278 Engine Switch Circuit Malfunction

  1. Remove the engine switch (RAV4_ACA30 RM0000020P000OX.html).

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    7 (SS1) - 5 (GND)
    		Pushed
    		Below 1 Ω
    2 (SS2) - 5 (GND)
    		Pushed
    		Below 1 Ω
    7 (SS1) - 5 (GND)
    		Not pushed
    		10 kΩ or higher
    2 (SS2) - 5 (GND)
    		Not pushed
    		10 kΩ or higher


NG
REPLACE ENGINE SWITCH (RAV4_ACA30 RM0000020P000OX.html)
OK


4.CHECK HARNESS AND CONNECTOR (ENGINE SWITCH - MAIN BODY ECU AND BODY GROUND)


    Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.2Az-Fe Starting.Starting System (W/ Entry And Start System). Dtc B2278 Engine Switch Circuit Malfunction

  1. Disconnect the E31 engine switch connector.

  1. Disconnect the E19 main body ECU connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E31-7 (SS1) - E19-10 (SSW1)
    		Always
    		Below 1 Ω
    E31-2 (SS2) - E19-9 (SSW2)
    		Always
    		Below 1 Ω
    E31-5 (GND) - Body ground
    		Always
    		Below 1 Ω
    E31-7 (SS1) or E19-10 (SSW1) - Body ground
    		Always
    		10 kΩ or higher
    E31-2 (SS2) or E19-9 (SSW2) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)